Complex fluid system circuits are known in the prior art which involve various circuit options within the fluid system based on the functionalities that are required.
For example, DE 10 2006 026 359 B4 describes an air conditioning system for vehicles which comprises a combined refrigeration system and heat pump system. Additional applications for generic valve block assemblies include refrigeration systems according to DE 10 2010 042 127 A1 and DE 10 2012 111 672 A1.
In the aforementioned complex circuit systems according to the prior art, valves for switching between refrigeration system operation and heat pump operation are described. In particular, these systems also employ externally controllable expansion valves. As valves and particularly as expansion valves in circuit arrangements of this type, spherical valves having an external seal arrangement according to DE 10 2012 111 467 A1, or spherical valves having an internal seal arrangement according to DE 10 2012 111 468 A1 are used in motor vehicle refrigerant circuits. The aforementioned spherical valves are operated both as switchover valves and/or shut-off valves, and as expansion valves.
In the prior art, for example in heat pump systems for use in automobiles, the valves are arranged individually in the system of lines.
Due to the weight of the valves, however, they cannot be supported by the lines alone, and must instead be mounted in the vehicle by means of mounting fixtures. To reduce the cost of assembly on the vehicle assembly line, multiple valves are usually combined with other components on a mounting plate to form sub-modules, which are then assembled and connected to the refrigerant lines. The sub-module is then supplied pre-assembled to the automobile manufacturer and is installed in the vehicle on the line at a reduced cost of assembly.
The disadvantage of the submodule design is that a multiplicity of individual valves may have to be connected to other components, for example heat exchangers, by means of individual refrigerant lines within a very small space. This necessitates a multitude of short lines which must be manufactured with great precision in terms of manufacturing specifications, such as bending radii and distances between bends or between bends and brazed-on parts. Due to the high complexity and the costs associated with this, the risk also exists that the complex line routes may allow oil traps to form in the submodule, and that increased pressure losses may impair the conductibility and efficiency of the heat pump system.
Moreover, in a heat pump system, due to the number of valves and connecting lines, the number of separating points and therefore the risk of external leakage is increased.
A further disadvantageous aspect is that, under certain circumstances, significant quantities of refrigerant may be stored in the inner volume of the connecting lines of the submodules. This increases the volume of refrigerant required to operate the system and therefore also the costs. This also gives rise to safety-relevant and environmentally relevant disadvantageous aspects.
DE 10 2006 060 923 A1 discloses a valve block having at least a first connection and a second connection, the two connections being connected to one another within the valve block for temporarily adjusting flow paths in a coolant system and/or for filling and/or emptying the coolant system, wherein the valve block is made of a refrigerant-resistant and pressure-resistant plastic.
One disadvantage of such embodiments is that, although valve blocks made of plastic can be relatively cost-effectively produced, their mechanical durability is frequently insufficient for mobile applications and for use at high pressures, such as those occurring in high-pressure refrigeration circuits.